In recent years, a hybrid working vehicle employing both an engine and a generator-motor (also called as a motor-generator) has been used as a working vehicle such as a construction machine, a civil engineering machine, an agricultural machine, a delivery vehicle, or a traveling vehicle. In many cases, a hybrid working vehicle has an arrangement in which an engine is transversely disposed in a rear portion of an upper surface of a swinging frame.
For such hybrid working vehicle in which an engine is transversely disposed, an arrangement structure of devices for a construction machine in which storage-related devices are provided in front of a swinging frame has been suggested (see Patent Document 1). Also, a hybrid construction machine having an arrangement in which an inverter for converting electric power for a battery is provided in an intake chamber of an engine room, in addition to an arrangement in which a battery is provided in front of a swinging frame as described above, has been suggested (see Patent Document 2).
FIG. 10 is a plan view illustrating the arrangement disclosed in Patent Document 1 as a related art 1 of the invention. As shown in FIG. 10, an engine room 52 is provided to house an engine 56 and engine-related devices 53 in a rear portion of an upper swing body frame 50. Also, storage-related devices 54 are provided at a right side in a front portion of the upper swing body frame 50, and high-pressure hydraulic devices 55 are provided at a left side of the rear portion of an operation room 51.
The storage-related device 54 includes a generator-motor 59 that works as a generator during regeneration and works as a motor when a driving torque of the engine 56 is not sufficient, a storage 60 that stores regenerating energy generated by a generator-motor 59 and supplies driving energy to the generator-motor 59, and an inverter 61 that controls the generator-motor 59.
As the storage 60, for example, a high-capacity capacitor capable of repeating charge and discharge at a high speed, a lithium ion battery or the like is used.
FIG. 11 is a plan view illustrating a cooling device disclosed in Patent Document 2 as a related art 2 of the invention. As shown in FIG. 11, a revolving frame 77 is provided as an upper swing body frame in a lower portion of an upper swing body 76 which is swingable on a lower traveling body of a hydraulic excavator. An operation room 78 is mounted on the revolving frame 77 as shown at a left side in a front portion. An engine room 81 is provided to be surrounded by an engine hood (not shown) and a counterweight 80 in a rear portion.
A radiator 83, a cooling fan 84, an engine 71, a generator-motor 73 and a hydraulic pump 72 are arranged in this order from a left side in the engine room 81. The engine room 81 is divided by a partition 82 extending along the radiator 83, and an intake chamber 81a is provided in the engine room 81 on a left side of the radiator 83. Inverters 79 are provided for controlling the generator-motor 73 in the intake chamber 81a. 
A hydraulic oil tank 85, a fuel tank 86, and an operation valve 87 are arranged at right side in a front portion of the upper swing body 76. A motor 75 for swing is mounted in a central portion of the upper swing body 76. The operation room 78 is provided at a left side of the front portion of the upper swing body 76 and a battery housing 89 is provided on the revolving frame 77 at a lower side of the operation room 78. A battery 74 is accommodated the a battery housing 89 and cooling air of an air conditioner for cooling the operation room 78 is sucked into the battery housing 89, so that the battery 74 can be cooled down.
Patent Document 1: JP-A-2004-169466
Patent Document 2: JP-A-2002-227241